TY - JOUR

T1 - Structural Insight into Strong Pt-CeO2 Interaction

T2 - From Single Pt Atoms to PtOx Clusters

AU - Derevyannikova, Elizaveta A.

AU - Kardash, Tatyana Yu

AU - Stadnichenko, Andrey I.

AU - Stonkus, Olga A.

AU - Slavinskaya, Elena M.

AU - Svetlichnyi, Valery A.

AU - Boronin, Andrei I.

PY - 2019/1/17

Y1 - 2019/1/17

N2 - Pt-CeO2 nanocomposites were obtained by coprecipitation, varying the Pt loading over a wide range of 1-30 wt %. The samples were calcined in air at 450-1000 °C. The Pt-CeO2 nanocomposites were investigated by a set of structural (X-ray diffraction, extended X-ray absorption fine structure (EXAFS), pair distribution function (PDF), and transmission electron microscopy) and spectroscopic (X-ray photoelectron spectroscopy and Raman spectroscopy) methods. Over the whole range of Pt loading, the main species were Pt2+ and Pt4+. They were localized either in a single-atom state or in the form of PtOx clusters on the ceria surface. The joint PDF and EXAFS modeling based on the combination of [Pt2+O4] single-atom and Pt3O4 structural fragments allowed us to propose the local structure of the PtOx clusters. The formation of such surface structures is associated with a distorted ceria surface on the Pt-CeO2 nanocomposites. We assume that the close arrangement of platinum ions in the PtOx clusters could be responsible for the effective redox properties of the samples.

AB - Pt-CeO2 nanocomposites were obtained by coprecipitation, varying the Pt loading over a wide range of 1-30 wt %. The samples were calcined in air at 450-1000 °C. The Pt-CeO2 nanocomposites were investigated by a set of structural (X-ray diffraction, extended X-ray absorption fine structure (EXAFS), pair distribution function (PDF), and transmission electron microscopy) and spectroscopic (X-ray photoelectron spectroscopy and Raman spectroscopy) methods. Over the whole range of Pt loading, the main species were Pt2+ and Pt4+. They were localized either in a single-atom state or in the form of PtOx clusters on the ceria surface. The joint PDF and EXAFS modeling based on the combination of [Pt2+O4] single-atom and Pt3O4 structural fragments allowed us to propose the local structure of the PtOx clusters. The formation of such surface structures is associated with a distorted ceria surface on the Pt-CeO2 nanocomposites. We assume that the close arrangement of platinum ions in the PtOx clusters could be responsible for the effective redox properties of the samples.

KW - WATER-GAS-SHIFT

KW - RAY PHOTOELECTRON-SPECTROSCOPY

KW - TEMPERATURE CO OXIDATION

KW - CATALYTIC-PROPERTIES

KW - PT/CEO2 CATALYSTS

KW - PLATINUM NANOPARTICLES

KW - LATTICE-RELAXATION

KW - PD/CEO2 CATALYSTS

KW - LOCAL-STRUCTURE

KW - DEFECT SITES

UR - http://www.scopus.com/inward/record.url?scp=85060134355&partnerID=8YFLogxK

U2 - 10.1021/acs.jpcc.8b11009

DO - 10.1021/acs.jpcc.8b11009

M3 - Article

AN - SCOPUS:85060134355

VL - 123

SP - 1320

EP - 1334

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

SN - 1932-7447

IS - 2

ER -